Virus cancer link

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The virus cancer link is the idea that some cancers are caused by viruses.

[edit] History

The theory that cancer could be caused by a virus began to be developed in 1911 by Peyton Rous. Rous transmitted solid tumors of chickens by transplanting tissue between them.

By the early 1950s it was known that viruses could remove and incorporate genes and genetic material in cells. It was suggested that these new genes inserted into cells could make the cell cancerous. Many of these viral oncogenes have been discovered and identified to cause cancer.

Studies since 2000 have found JC virus in malignant colon tumors and suggested that the virus may be linked to colon cancer.

There are many other examples of viruses associated with cancer. DNA tumour viruses such as Human Papilloma Virus (HPV) cause transformation in cells through interfering with tumour suppressor proteins such as p53. Interfering with the action of p53 allows the cell infected with the virus to be able to move into a different stage of the cell cycle allowing the virus genome to be replicated forcing the cell into the S phase of the cell cycle could cause the cell to become transformed. Herpes viruses have also been associated with cancers human herpes virus-8 is associated with Kaposi’s sarcoma (a type of skin cancer.) Another virus linked with cancer is Epstein Barr Virus (EBV), there are four types of cancers associated with this virus. Burkitts lymphoma which is the most common childhood cancer in Equatorial Africa[1], is also associated with the malaria parasite, BL may be a polyclonal disease where more than one pathogen plays a role in the cell transformation. Nasopharyngeal cancer, B-cell lymphomas and Hodgkins lymphoma have also been linked with this virus. It is not only DNA viruses that are associated with cancers some RNA viruses have also been associated such as the Hepititis C Virus as well as Human T cell leukaemia virus-1 (HTLV-1)